In a survey last month, 80% of developers admitted they don't earn enough money from building apps to support an independent business and 59% of apps don't generate enough revenue to break even on development costs.

These depressing findings, and more summarized in this infographic, come from a survey by App Promo, a company that aims to help developers achieve success through its app marketing and strategy services.

The goal of its First Annual App Developer Survey, conducted online from April 6 - 22, 2012 was to:

get a deeper statistical understanding on how developers are doing with their applications especially from a monetization and marketing perspective

Developers for iOS, Android, BlackBerry, Windows and Symbian were encouraged to participate by a prize draw for $1,000 in App Store Optimization services. According to the survey report, over a hundred (102 to be exact) app developers took part.

What we found is that those developers that spend money and time on marketing outside of the app stores found the most success based on the revenue they had earned for their app. This core finding echoes what webelieve as a leading app marketing and strategy firm, that in order to make an app a successful business you need to ensure that you have a budget and time allocated to marketing and promoting your app.

This must be a biased survey - and the reality is probably that an even greater proportion of apps fail in revenue terms - but the overall message holds - it is not enough simply to build an app and expect to make a fortune.